From a viewpoint of saving resource, an erasing apparatus erasing a developer image by heating a record medium forming image using an erasable developer is put to practical use.
However, in a condition that a manuscript or base paper, a confidential document and the like, which are not expected to be erased, are mixed in the thrown record medium, a conventional erasing apparatus indiscriminately carries out erasing processing with other record medium.
Particularly, a condition that an erased character can be distinguished also exists for the confidential document, and therefore, when the confidential document is processed as a reusable document, the confidential disclosure possibly occurs.